Direct Aldehyde Csp2 -H Functionalization through Visible-Light-Mediated Photoredox Catalysis.

The development of methods for carbon-carbon bond formation under benign conditions is an ongoing challenge for synthetic chemists. In recent years there has been considerable interest in using selective C-H activation as a direct route for generating reactive intermediates. Herein, the use of visible-light-mediated dual photoredox organocatalysis as a mild and effective method for Csp2 -H activation of aldehydes is reported, resulting in the generation of acyl radicals. These nucleophilic acyl radical species can undergo either addition to electrophilic alkenes or nickel-catalyzed cross-coupling reactions to provide a quick access to broad range of unsymmetrical ketones, which are abundantly found in many organic building blocks.